FIG. 267. BOTRYCHIUM
LUNARIA, showing Habit,
Capsule, and Spores.
B. lunarioides (Lunaria-like). A variety of B. ternatum.
B. obliquum (oblique). A variety of B. ternatum.
B. subcarnosum (sub-fleshy). A synonym of B. daucifolium.
B. ternatum (ternate).* sti. 1in. to 2in. long. petiole of the sterile segments 2in. to 4in. long, the latter 3in. to 6in. each way, deltoid, tri- or quadripinnatifid; lower pinnæ much the largest. fertile peduncle 6in. to 9in. long; panicle 1in. to 6in. long; deltoid, very compound. Nootka and Hudson's Bay territory. Several so-called species come very close to this, including australe, lunarioides, and obliquum, which are only geographical varieties. Greenhouse species.
B. virginianum (Virginian).* sti. 3in. to 18in. long. sterile segments sessile, 4in. to 12in. each way, deltoid, quadripinnatifid; lower pinnæ much the largest; pinnules oval-oblong, close, cut down to the rachis into finely cut linear-oblong segments. fertile peduncle equalling or exceeding the sterile part of the plant when mature; panicle 1in. to 4in. long, loose, oblong. Oregon, and North United States, 1790. A hardy species in sheltered places. (H. G. F. 29.)
BOTTLE-GOURD. See Lagenaria.
BOTTLE-TREE. See Sterculia rupestris.
BOTTOM HEAT. This is usually secured by passing hot-water pipes through an air chamber, or a water tank, beneath a bed of plunging material. The covering of the tank or chamber is best made of slate. The heat must be regulated according to the requirements of the subjects grown; this is easily accomplished by using the valve. A thermometer should be placed in the tank or bed. Bottom-heat is indispensable for propagating plants from seeds and cuttings, especially in spring. See Heating and Hotbeds.
BOUCEROSIA (from boukeros, furnished with buffaloes' horns; in reference to the curved lobes of the corona) ORD. Asclepiadaceæ. A genus of greenhouse succulent perennials, allied to Stapelia, and requiring the same culture. Flowers numerous, terminal, umbellate; corolla sub-campanulate, five-cleft; segments broadly triangular, with acute recesses; stramineous corona fifteen-lobed; lobes disposed in a double series; the five inner ones opposite the stamens and lying upon the anthers; the rest exterior, erect, or a little incurved at apex, adhering to the back of the inner ones. Branches and stems tetragonal, with toothed angles.
FIG. 268 BOUCEROSIA EUROPÆA.
B. europæa (European). fl. purple-brown, yellow. Summer. h. 4in. Sicily, 1833. SYNS. Apteranthes and Stapelia Gussoniana. See Fig. 268. (B. R. 1731.)
B. maroccana (Morocco).* fl. dark red purple, with yellow concentric lines. Summer. l. minute, trowel-shaped, deflexed at tip of stem angles. h. 4in. Morocco, 1875. (B. M. 6137.)
BOUCHEA (named after C. and P. Bouche, German naturalists). ORD. Verbenaceæ. A small genus of stove or greenhouse evergreen herbs or sub-shrubs. Flowers sub-sessile, in spicate racemes, which are either terminal or in the forking of two branches; corolla funnel-shaped. Leaves opposite, toothed. They thrive in a well-drained compost of loam and sandy peat. Propagated by cuttings, placed in sand, under a glass, and in a gentle heat, during spring.